To meet service requirements in different scenarios, a network slicing method may be used. That is, multiple network slices constitute a network, and a single network slice may be defined as a set of logical network function entities supporting a communications service requirement in a specific scenario, for example, a network slice supporting communication of a large quantity of machine devices or a network slice supporting a mobile broadband service. There may be multiple slicing manners for network slicing. For example, a core network may be sliced, an access network may be sliced, or a core network and an access network may be sliced together. A dedicated core network (DCN for short) defined in the 3rd Generation Partnership Project (3GPP for short) is a solution for slicing a core network.
In an existing 3GPP standard solution, a core network device triggers a rerouting process of an access network device. When receiving a terminal request message sent by the access network device, such as a registration request or an update location request, a core-network control function entity may determine whether the core-network control function entity belongs to a specific DCN that serves the access network device. If no, the core-network control function entity sends information about the specific DCN of the access network device, to request the access network device to reroute the terminal request message to a core-network control function entity in the specific DCN of the access network device.
However, in the foregoing solution, the rerouting process of the access network device requires a large quantity of communication signaling interactions, increasing a processing delay and decreasing communication efficiency.